Plumbing Glossary

A- B- C- D- E- F- G- H- I- J- K- L- M- N- O- P- Q- R- S- T- U- V- W- X- Y- Z

~A~
ABS: Plastic used in the manufacture of drain, waste, and vent pipes.
Acrylic: A glassy thermoplastic cast and molded shapes to form the surface of bathtubs, whirlpools and shower bases.
Aerator: A small device at the end of a faucet spout which is used to mix air into flowing water.
Angle Stop: A shutoff valve between the faucet/toilet and the water pipes. Connects the water supply in a wall and its outlet angles up 90 degrees toward the faucet/toilet.
Anti-Scald: A valve that restricts water flow to help prevent burn injuries.
Anti-Siphon: A device that prevents water from flowing back into supply lines, possibly contaminating the water supply.

~B~
Backflow: When water traveling from one device backs into any part of the main water supply, usually caused by siphoning.
Backflow Preventer: A device used to prevent backflow. In some areas, plumbing codes require a backflow preventer.
Ballcock: A fill valve device in a toilet tank.
Basin: A circular vessel with slopping sides used to hold water for washing.
Bidet: Used for washing posterior areas of the body. It is floor mounted, usually next to a toilet.
Bushing: A pipe fitting used for joining pipes with different diameters together. A bushing is threaded on both the inside and outside.

~C~
Cast Iron: Heavy metal formed by casting in molds.
Centerset: A style of faucet that has the spout and handles combined into a single part. Usually installed on a lavatory with 4" center-to-center faucet holes.
Ceramic Disk Valve: A type of valve that relies on two-part revolving disks in a sealed cylinder. Each disk has a port in it that, when aligned with the other, will allow water to pass through.
Cock: A valve used for regulating water flow.
Compression Fitting: A sealed pipe connection without soldering. As you tighten a nut on one fitting, it compresses a washer around the second pipe, forming a watertight closure.
Compression Valve: Works by lowering or raising a stem. By turning the faucet handle it causes the stem to drop or rise, allowing water to pass through the valve.
Console Lavatory: A lavatory in which the basin is attached by table or piano legs at the front and to a wall at the back.
Coupling: Straight, fitting with female connections at both ends.
Cover: The top portion of a toilet seat, the top lid on a toilet's tank.

~D~
Diverter: Valves which have one inlet and direct water to one of two outlets. Diverters are normally used with shower risers, hand showers, and kitchen faucet sprayers.
DWV: Drainage, Waste & Vent. Pipes in a plumbing system that remove waste water.

~E~
Elbow: Angled fitting that changes the direction of the water line.
Enamel: An opaque vitreous composition applied to the surface of metal fixtures such as cast iron tubs and sinks.
Escutcheon: A trim piece that is used to conceal the faucet stem and the hole in the fixture.

~F~
Female IPS: Pipe connection where the threads are on the inside of the fitting.
Fiberglass: Glass in a fibrous form used in making the body of bathtubs.
FIP: Female Iron Pipe. Standard threads that are on the inside of a pipe fitting.
Fitting: A general term that usually refers to faucets, shower valves, tub fillers, or various piping parts such as tees or elbows.
Fixture: A broad based term usually referring to sinks, tubs, toilets, and basins.
Flex Hose: A flexible pipe usually made of braided stainless steel.
Flow Rate: The rate which water is discharged from an outlet.

~G~
GPM: Gallons Per Minute. Unit of measurement by which flow rates of faucets and showerheads are measured and regulated.
GPF: Gallons Per Flush. Unit of measurement which flow rates of toilets are measured and regulated.
Gelcoat: Material used to form the surface of some fiberglass bathtubs or showers, it is a colored, polyester resin.

~H~
Hand shower: A showerhead designed with a handle that is attached to a water supply with a flexible hose.
Hose Bibb: Outdoor faucet with hose threads on the spout.

~I~
ID: Inside Diameter. Diameter measurement from the inside of a pipe. Commonly used for sizing pipe.
Inlet: Opening providing an entrance or intake.
IPS: Iron Pipe Size. Pipe thread sizing system. The measurement of the outside diameter of a pipe.

~J~
Jacuzzi: Often misused to mean any whirlpool tub.

~K~

~L~
Lavatory: Bathroom or washroom sink.
Lid: The removable cover on a toilet's tank.

~M~
Male IPS: Pipe connection where the threads are on the outside of the fitting.
MIP: Male Iron Pipe. Standard external threads on pipe and fittings.
Mini Spread: Made small enough that it will fit 4" center to center faucet holes. A special style of lavatory faucet having separate spout and handles.
Mixing Valve: Mixes hot and cold water in the valve to get a set temperature before delivery.

~N~
Nipple: A short pipe threaded on both ends installed between fittings.
Nominal Size: Used for identification only, not literal dimensions.

~O~
O ring: Typically in a compression fitting, this round rubber washer is compressed to make a watertight seal .
OD: Outside Diameter. Common method for sizing pipe, this is a measurement of the diameter of a pipe as taken from the outside edge.
Offset: A tubular component which permits the offsetting of a drainage run in the same basic direction.
Open Front: A style of toilet seat where there is an open space at the front. Considered more sanitary in commercial applications.

~P~
P trap: P-shaped section of drain pipe that water is trapped in, blocking gases from escaping through the drain. Prevents sewer odors from escaping into your home.
Pedestal Lavatory: A lavatory in which the bowl is supported by a single pedestal leg.
Pop-Up Drain: Relies on a lever or rod to lift or pop up the drain stopper. A drain mechanism.
Powder Coat: A technique for applying paint to metal surfaces. The metal is covered with a powder of dry paint particles and is baked in an oven.
P. O. PLUG: Plug Outlet. A style of drain outlet that is closed by a rubber stopper, or plug. Used for lavatories.
Pop Up Assembly: Installed on a lavatory, the drain mechanism of a faucet.
Porcelain: A ceramic ware that consists of kaolin, quartz and feldspar, and is white. Fired at high temperatures on steel to make the surface of bathtubs and kitchen sinks.
Pressure Balancing Valve: Maintains a constant water temperature by using a mixing valve that balances incoming hot and cold water supplies.
PVC: PolyVinyl Chloride. A white plastic used to manufacture water supply pipes.
PVD: Physical Vapor Deposition. A durable zirconium or titanium coating that resists scratches, tarnish, and corrosion.

~Q~

~R~
Reducer: A pipe fitting used for joining pipes with different diameters together. A bushing is threaded on both the inside and outside.
Rim: The inside edge of a toilet bowl. The edge of a lavatory or sink.
Riser: Vertical pipe that feeds water to a fixture.
Rough-in: The unfinished ends of drain or supply lines marking where fixtures and drains will be installed.

~S~
Seat: The stem will move against the seat to open and close the valve. The fixed part of a valve.
Self Rimming: A style of bathroom lavatory or kitchen sink with a finished lip or rim that installs on top of a counter without requiring a metal sink rim.
Sink: A stationary basin connected with a drain and water supply for washing and drainage.
Slip Joint: A connection made with compression fittings.
Spud: A section of pipe or threaded fitting that completes a connection.
Stem Assembly: Moving part of the valve that controls the amount and temperature of water released.
Stem: Projects through the faucet valve and to which the handle is installed. A small shaft or rod.
Stop: The valve that allows water supply to be cut off to one fixture without affecting the water supply to the entire house or building. Common for use with clawfoot tubs, sinks, and toilets.
Straight Stop: Shutoff valve that is installed between the floor and the faucet or toilet on a supply line, and does not change direction.

~T~
Tailpiece: Tubular part of a lavatory drain that runs from the drain flange to the trap.
Tee: A T-shaped fitting with three openings.
Thermostatic Valve: A mixing valve that automatically maintains the temperature setting by regulating fluctuations in water temperature at the water inlets and immediately adjusting the ratio of hot and cold water that is discharged by the valve.
Trim Kit: The outside decorative parts that hide a faucet rough-in.
Trip Lever: The lever that opens and closes the drain on a bathtubs waste & overflow. The flush handle and actuating arm on a toilet tank.

~U~
Undercounter: Positioned under the cutout of the countertop is this style of lavatory.
Union Nut: Joins two sections of pipe using a fitting.

~V~
Vacuum Breaker: An anti-siphon device which prevents the backflow of water into the supply system.
Valve: A device that regulates water flow.
Vanity: A storage cabinet beneath the counter usually found in bathrooms.
Vessel: A style of basin that installs partially into the counter rather than fully into the counter. The portion of the fixture rising above the counter has a finished exterior.
Vitreous: Found on some plumbing fixtures, consisting of glass. Used as a surface material.

~W~
Waste and Overflow: The drain assembly for a bathtub. The drain at the top removes the overflow water during tub filling and the drain at the bottom removes waste water when the tub is drained.
Water Closet: Toilet.
Widespread: Usually 8" from center of handle-to-handle, this style of bathroom lavatory faucet has separate spout and handles.
Whirlpool Tub: A whirlpool bathtub system. The system recirculates the tub water and mixes in air to create hydro therapy with jet inlets.

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~Y~

~Z~